Date   

Confused here

GM6VXB
 

Today I had my thrid (or is it fourth) advisory from 'groups.io' that I  my account was bouncing Emails back to them.


This has got me confused as I have tried four different ways of receiving Emails,

To my Iphone.
To Windows 10 mail.
To a spare Windows 7 laptop.
To (Good old) Windows XP 'Outlook Express'.

Whichever I am using, I always see all the messages that 'Groups.io' are saying have been bounced back to
them.
All the advisories have been for UKMicrowave group messages.

Is this a problem with the devices and software I am using, or is a 'BTinternet.com' issue ?.

Martin, GM6VXB(/P)
(on the wind blown Hebrides (IO67 today IO68 tomorrow)


GW4NOS PI Beacon 10368.450MHZ

John Fell
 

With the RS about at this time you my want to look for Roger's beacon which is currently pointing around 130 degrees from his QTH in IO81 NNW of Cardiff.
He is using a 60 degree wide horn on his mast top .
I have decoded his signal for the first time an hour ago at -21 level and around 20 subsequent decodes around that level .A few degrees of EL helped.

73
John
G0API


Spid

on4cjq@...
 

I have the BIG RAS(AZ/EL) since 10y or so. Only 1 problem occurred. when using it on sat tracking i noticed that it had an offset after every pass.
It seemed i had 1.2°  instead of 1° per movement. You can test it by for example push it 90 times to turn 90°, if you have an offset at the end, the ROT2PROG chip is not good.
Contacted SPID in Poland, and they said to sent me a new chip... and i received a completely new controller box :)). I sent mine back. Since then never had any problems for sat tracking and for my /p µwave contest operations.
For 2y  i also use the Spid RAU(AZ) for quick /p ops and use it also for /p contest activity in combo with a Yaesu 550 for EL. Rau works ok, 550 is getting old and considering a second BIG RAS.
Noise: BIG RAS only on 2m( other bands not checked); RAU no noise problems.

73's
Jerry,ON4CJQ


Re: duel band feed

Neil Smith G4DBN
 

Hi Daniel, I use that technique on 3/6cm using a 4.5 degree altitude change with one horn above the other and it certainly works well. It will be interesting to see if the combined antenna performs worse than two separate single band versions.

This is a 3/6cm version I made for Tony, his dish is mounted upside-down with the arm at the top.

http://www.g4dbn.uk/wp-content/uploads/2019/08/DMU-extension3.jpg

Neil

On 09/03/2020 09:33, Daniel wrote:
Hi Neil,

my simple aproach was to mount pyramidal horns for 6 and 9cms (G4NNS website) to the left and right of the 10GHz feed.
The result is an 8 deg offset in azimuth to the left and right for the 2 bands.
Since the opening angles are considerably wider for the lower bands, pointing is not a problem.
The loss in gain due to displacement of the feed from the center is negligible (~1 dB max.) and isolation between bands is not a problem.
Here is a foto of the 6 and 3 cms feeds. I decided later to move 9 cms to my bigger dish for more gain (prime focus for 23/13/9 cms)
https://s3.amazonaws.com/files.qrz.com/e/dl3iae/IMG_0794.JPG
Never the less I really envy your machinery and mechanical skills. Excellent stuff!

Daniel
DL3IAE
_._,_._,_



TR120 board - UK horizontal polarisation

Chris G0FDZ
 

Hi folks

Thanks to Barry G8AGN for bringing this potential problem to my attention.

The TRA120 board’s as shown in all the photos are mounted so that the polarisation is vertical. In the UK (and probably Europe too) we have used horizontal polarisation for many years on all the microwave bands.

For maximum compatibility with existing equipment, the UKuW Group recommends that the UK uses horizontal polarisation and this simply means that the board will need to be mounted in a box with the board at 90 degrees to the indicated position. The arrow should point left or right rather than 'vertically' as shown, and as the board is square this should not present a problem.

If there is a cross polarisation problem between stations then the consequences can be severe, as there is likely to be an extra 20dB loss due to polarisation error, and this will mean for most contacts the difference between success or not (apart from local contacts).

The compatibility point is also applicable to the frequency used and the user will just need to select 122.4 GHz as the UK frequency.

Chris Whitmarsh G0FDZ

UKuW Group


Virus-free. www.avg.com


Re: duel band feed

Daniel DL3IAE
 

Hi Neil,

my simple aproach was to mount pyramidal horns for 6 and 9cms (G4NNS website) to the left and right of the 10GHz feed.
The result is an 8 deg offset in azimuth to the left and right for the 2 bands.
Since the opening angles are considerably wider for the lower bands, pointing is not a problem.
The loss in gain due to displacement of the feed from the center is negligible (~1 dB max.) and isolation between bands is not a problem.
Here is a foto of the 6 and 3 cms feeds. I decided later to move 9 cms to my bigger dish for more gain (prime focus for 23/13/9 cms)
https://s3.amazonaws.com/files.qrz.com/e/dl3iae/IMG_0794.JPG
Never the less I really envy your machinery and mechanical skills. Excellent stuff!

Daniel
DL3IAE


Cardiff Round table.

R Hopkins
 

Hi all

I had a really good day at the round table on Saturday at the round table. Just like to say thank
you to everyone involved in organising it.

Cheers

Roger GW4NOS


Re: equipment for sale

mike G6TRM
 


OK Ben, you offered to buy, that's an offer..
I Informed you I had multiple"Bids" I used the word by mistake as I was discussing with a friend what I should do about all the multiple offers I had received on a number of items. He and I discussed using a once only bid from each party to resolve the problem.. I had the word "bids" on my mind and used it incorrectly.  you replied you didn't realise I wanted bids, I  immediately apologized and confirmed I meant offers.
As I have already mentioned I did not go in that direction.
Why If I was looking for bids would I not contact someone??? how does that work?..How were your comments helping?. you were just stirring things up.
And again you make comment on things you know nothing about....What new hobby do I have?   losing my wife and house is that my new hobby?
 
G6TRM
 
 
 

----- Original Message -----
Sent: Sunday, March 08, 2020 7:25 PM
Subject: Re: [UKMicrowaves] equipment for sale


To All,
re:- my equipment for sale..
IF anyone wants to know how I am selling my items and who gets what, I suggest you ask ME not BEN.

 
Ben, Sadly you were unsuccessful on the 2 item you placed offers on...
 
Mike G6TRM

I didn't make you an offer Mike. I said I'd buy them at the price you stated to which you replied you were looking for bids or offers (copy of email to anyone who wants). 

I tried to tell the other chap what you had told me. I was not suggesting anything.

Kindly do not infer that I  was doing anything other than that. 

I'm glad you got the most for your items and hope that you enjoy your new hobby. 

Ben. 


Re: equipment for sale

militaryoperator
 


To All,
re:- my equipment for sale..
IF anyone wants to know how I am selling my items and who gets what, I suggest you ask ME not BEN.
 
Ben, Sadly you were unsuccessful on the 2 item you placed offers on...
 
Mike G6TRM

I didn't make you an offer Mike. I said I'd buy them at the price you stated to which you replied you were looking for bids or offers (copy of email to anyone who wants). 

I tried to tell the other chap what you had told me. I was not suggesting anything.

Kindly do not infer that I  was doing anything other than that. 

I'm glad you got the most for your items and hope that you enjoy your new hobby. 

Ben. 


Re: equipment for sale

mike G6TRM
 


To All,
re:- my equipment for sale..
IF anyone wants to know how I am selling my items and who gets what, I suggest you ask ME not BEN.
To be clear, on Items where I received multiple offers, It was suggested to me to consider going with a one more final once only bid, to select a "winner"
After considerable thought, I decided instead to pick one "out of a hat"
I have received many emails with offers and also requests for further information, as many of you realise, this takes a great deal of time to deal with.
Most people who have made offers have been successful to some degree..This is intentional on my part, my attempt to ensure that as many as possible benefit from my "collection"
Some have expected to get everything they asked for, almost demanding in some cases.  Most understand my sadness in having to sell it all, The years it took me to collect it and in general have been very polite and prepared to wait while I get my "ducks in a row"
Some equipment has been sent out, some has been collected, some is due to be sent out very soon, some has to be collected very soon and some has yet to be finalized.
NO ONE has been asked to make a further "BID"
I have a second list that I have to prepare, it will be later that I expected..
Please be patient, I am trying my best.
 
Ben, Sadly you were unsuccessful on the 2 item you placed offers on...
 
Mike G6TRM
 

----- Original Message -----
Sent: Sunday, March 08, 2020 1:42 PM
Subject: Re: [UKMicrowaves] equipment for sale


Yes, I had a reply re some equipment I wanted.   
Patience OM :-)



On Sun, 8 Mar 2020 at 08:37, g3zqu via Groups.Io <g3zqu=btinternet.com@groups.io> wrote:
Hi.
Has anybody had a reply from Mike regarding his items for sale. Had sent a couple of emails but not had any reply in over a week!
Martin G3ZQU


Seems he wanted bids or offers Martin, the figures he quoted were the base line it seems so maybe there are still bids he needs to consider on the items you and I wanted. Seems others have been more successful it seems. 

Ben


Re: equipment for sale

militaryoperator
 


Yes, I had a reply re some equipment I wanted.   
Patience OM :-)



On Sun, 8 Mar 2020 at 08:37, g3zqu via Groups.Io <g3zqu=btinternet.com@groups.io> wrote:
Hi.
Has anybody had a reply from Mike regarding his items for sale. Had sent a couple of emails but not had any reply in over a week!
Martin G3ZQU


Seems he wanted bids or offers Martin, the figures he quoted were the base line it seems so maybe there are still bids he needs to consider on the items you and I wanted. Seems others have been more successful it seems. 

Ben


Re: equipment for sale

mike G6TRM
 


Hi Martin,
 
An email was sent out to you on the 4th, however to confirm I have sent it out to you again...
 
 
To others...There are a few offers that I have replied to, That I am yet to receive a reply..can you please check your email in boxes.
My apologies to others who may not yet have heard anything from me, the process is more involved and is taking much longer than I anticipated..If you unsure or want an update please contact me directly..
 
 
thanks
 
Mike G6TRM
 

----- Original Message -----
Sent: Sunday, March 08, 2020 8:37 AM
Subject: Re: [UKMicrowaves] equipment for sale

Hi.
Has anybody had a reply from Mike regarding his items for sale. Had sent a couple of emails but not had any reply in over a week!
Martin G3ZQU


Re: Activity List for the UK Microwave Group Low Band Contest, Sunday 8th March

Graham - G3YJR
 

On Sat, Mar 7, 2020 at 10:04 AM, John Quarmby wrote:
Callsign: G3YJR
Locator: IO93FJ
Bands: 1296 8W; 2300, 2320 MHz 25W
            40el Wimo on 13cm, 44el Wimo on 23cm
Talkback: ON4KST, direct CQ
Times: after 1400 Sun, visitors permitting


Re: No Planes visible on Airscout

Dave - G4RQI
 

Thanks for the tip... I downloaded the new version last night which is much improved and was rewarded with DF0MU and ON4CJQ/P via AS on 23cm SSB.

73 David -G4RQI


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of Martin - GM8IEM <martinhall@...>
Sent: Wednesday, March 4, 2020 10:37:47 AM
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] No Planes visible on Airscout
 

P.S. The latest version is v.1.3.1.0 which may be downloaded from http://www.airscout.eu/downloads.html  The plane feeds are much improved.

Martin

 

From: UKMicrowaves@groups.io On Behalf Of Martin - GM8IEM
Sent: 04 March 2020 10:35
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] No Planes visible on Airscout

 

Hi Maarten,

I found the same recently with v1.2.0.5.  However, if you upload the latest version it works fine.

73, Martin

GM8IEM – IO78HF

 

 

 

From: UKMicrowaves@groups.io On Behalf Of Maarten PA0MHE
Sent: 04 March 2020 10:18
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] No Planes visible on Airscout

 

Yesterday (during UKAC) and today I don't see any planes on my Airscout V1.2.0.5, Yes there is less flying due to Corona but....... Now I have as "Plane feed" Airscout Web Server, but I tried also the others in the list.
Any idea how to fix ?


Re: equipment for sale

Andy G4JNT
 

Yes, I had a reply re some equipment I wanted.   
Patience OM :-)



On Sun, 8 Mar 2020 at 08:37, g3zqu via Groups.Io <g3zqu=btinternet.com@groups.io> wrote:
Hi.
Has anybody had a reply from Mike regarding his items for sale. Had sent a couple of emails but not had any reply in over a week!
Martin G3ZQU


Re: equipment for sale

g3zqu
 

Hi.
Has anybody had a reply from Mike regarding his items for sale. Had sent a couple of emails but not had any reply in over a week!
Martin G3ZQU


Re: DB6NT 3.4GHz G3 Transverter circuit - Ionica PA

David GM6BIG
 

Hi Howard,

You have done the test we were all scared to try !
Did the PA survive, and if so, how long was it powered for ?

I still have various Ionica bits if its bad news.

Cheers, DAvid GM6BIG

On 06/03/2020 22:50, g4cch_1 wrote:

Hi Graham,

The SMCJ15 was dead short.Took some finding, I was expecting it to be near the end of the board where all the connections are.

Just lifted one end, then everything ok again.

Got problems elsewhere to fix now. The two 12V isolated regulators in my psu for my Ionica PA didn't like it either
Circuit didn't failsafe, so ended up with +10V on the Ionica with no other voltages.
Expecting Ionica to be kaput also...

Enough for today, will see what I can do tomorrow

73 Howard G4CCH

--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus


Re: duel band feed

DD1US
 

Hi Neil,

 

I think the design from Rasto should be very robust. I have not tried it myself. Good luck with your project.

 

Kind regards

 

Matthias

 

www.dd1us.de

 

 

Von: UKMicrowaves@groups.io <UKMicrowaves@groups.io> Im Auftrag von Neil Smith G4DBN
Gesendet: Samstag, 7. März 2020 19:22
An: UKMicrowaves@groups.io
Betreff: Re: [UKMicrowaves] duel band feed

 

Hi Matthias, that was the article in DUBUS that started me thinking about a version for 3.4/10GHz, but I was concerned that the clearance between the probes and the centre tube might not be sufficient with the smaller outer guide tube at 3.4GHz.  I had not realised that Rasto had used thick-walled tube with an OD or 33mm for the 10GHz guide, so perhaps there would be sufficient space.

Looking at the finished antenna, I estimate the probes are 24.5mm.  The the ID of the tube is given as 112mm, the OD of the inner guide is 33mm. If those are scaled for 2405MHz/3401MHz, the dimensions are 80mm ID, 18mm probes and 23mm inner guide OD.  In reality, I would use 76mm ID aluminium tube, and 22mm guide OD, so it should be feasible to make probes which will give a good return loss without getting too close to inner guide. I could then take the inner guide out through the backshort and machine a coaxial probe or a transition to a WR90 flange.

I would use the HB9PZK dimensions for a Rexolite lens on the 10GHz guide.  That keeps the size of the inner guide as small as possible. Perhaps the 3.4GHz pattern would be acceptable on an f/d 0.65 dish without an additional choke ring?

I will try a simulation. If it looks OK, I'll make an antenna as a test.  This is for terrestrial use by a friend. I am not looking for ultimate EME performance.  It must be robust, waterproof and not too heavy.

Thanks for reminding me about the article.

Neil G4DBN

On 07/03/2020 16:58, DD1US wrote:

Hi Neil.

 

Did you have a look at this approach from Rasto OM6AA:

 

http://www.om6aa.eu/A_Simple_S_X_Dual_Band_Coaxial_Feed_for_Satellite_Communication_FV.pdf

 

Kind regards

 

Matthias

 

www.dd1us.de

 

 

Von: UKMicrowaves@groups.io <UKMicrowaves@groups.io> Im Auftrag von Neil Smith G4DBN
Gesendet: Samstag, 7. März 2020 16:03
An: UKMicrowaves@groups.io
Betreff: Re: [UKMicrowaves] duel band feed

 

Here's a thought then. Imagine the 10GHz waveguide and lens from a POTY, with an HB9PZK lens in a 22mm tube, about 70mm long, supported coaxially within a cylindrical 9cm horn. At the mouth of the 9cm tube, the 22mm tube is supported by a thin disk of HDPE or cross-linked polystyrene which also seals the end 9cm horn against water and insects.. The 22mm tube has a probe feed, with an air-spaced coaxial tube (or maybe semi-rigid coax?) which passes through the wall of the 9cm tube to a connector for 10GHz.  The backshort of the 22mm tube is either flat or perhaps has a long taper so it doesn't interfere too much with the 9cm horn fields.  The 9cm horn has a probe feed as usual.  Problem with that arrangement is that the feed for the 3cm horn is parallel to the electric field of the 9cm horn if both use the same polarisation.

The 9cm probe would normally be about 19mm long in a simple cylindrical horn, but as the ID is around 62mm, if I ran the 22mm tube right through the backshort, would I be able to excite the correct mode to get linear polarisation at the mouth of the 9cm horn?  I suppose I should model it and see what happens.  There was an article in DUBUS a couple of years ago with a 13/3cm dual horn which used that principle, but had four tapered probes fed in quadrature to get circular polarisation.  The clearances are a lot less stringent with 2.4 and 10GHz.

Is it worth pursuing this approach? Is there a trick to use a short horn near the opening but get the feed to it without upsetting things on 9cm?  I could use a loop or tee to excite the 10GHz feed, with a coax feed through the backshorts of the 9cm horn, but aren't they a bit more lossy than a probe? Also not easy to adjust.

Couple of renders and a wobbly animation of the initial (obviously hopeless) ideas at http://www.g4dbn.uk/?p=1442

The 3.4GHz horn without choke ring looks like this in real life, so just imagine the 10GHz bit of a lensed POTY hanging coaxially in space with a support disk of thin dielectric material:

I have a lawn tractor to repair now, plus a teetering pile of 'prints for machining jobs, hence no visit to Cardiff or playing in the contests this weekend.

Neil G4DBN

-- 
Neil
<a href="http://g4dbn.uk/"><small>g4dbn.uk</small></a>


Re: duel band feed

Neil Smith G4DBN
 

Hi Matthias, that was the article in DUBUS that started me thinking about a version for 3.4/10GHz, but I was concerned that the clearance between the probes and the centre tube might not be sufficient with the smaller outer guide tube at 3.4GHz.  I had not realised that Rasto had used thick-walled tube with an OD or 33mm for the 10GHz guide, so perhaps there would be sufficient space.

Looking at the finished antenna, I estimate the probes are 24.5mm.  The the ID of the tube is given as 112mm, the OD of the inner guide is 33mm. If those are scaled for 2405MHz/3401MHz, the dimensions are 80mm ID, 18mm probes and 23mm inner guide OD.  In reality, I would use 76mm ID aluminium tube, and 22mm guide OD, so it should be feasible to make probes which will give a good return loss without getting too close to inner guide. I could then take the inner guide out through the backshort and machine a coaxial probe or a transition to a WR90 flange.

I would use the HB9PZK dimensions for a Rexolite lens on the 10GHz guide.  That keeps the size of the inner guide as small as possible. Perhaps the 3.4GHz pattern would be acceptable on an f/d 0.65 dish without an additional choke ring?

I will try a simulation. If it looks OK, I'll make an antenna as a test.  This is for terrestrial use by a friend. I am not looking for ultimate EME performance.  It must be robust, waterproof and not too heavy.

Thanks for reminding me about the article.

Neil G4DBN

On 07/03/2020 16:58, DD1US wrote:

Hi Neil.

 

Did you have a look at this approach from Rasto OM6AA:

 

http://www.om6aa.eu/A_Simple_S_X_Dual_Band_Coaxial_Feed_for_Satellite_Communication_FV.pdf

 

Kind regards

 

Matthias

 

www.dd1us.de

 

 

Von: UKMicrowaves@groups.io <UKMicrowaves@groups.io> Im Auftrag von Neil Smith G4DBN
Gesendet: Samstag, 7. März 2020 16:03
An: UKMicrowaves@groups.io
Betreff: Re: [UKMicrowaves] duel band feed

 

Here's a thought then. Imagine the 10GHz waveguide and lens from a POTY, with an HB9PZK lens in a 22mm tube, about 70mm long, supported coaxially within a cylindrical 9cm horn. At the mouth of the 9cm tube, the 22mm tube is supported by a thin disk of HDPE or cross-linked polystyrene which also seals the end 9cm horn against water and insects.. The 22mm tube has a probe feed, with an air-spaced coaxial tube (or maybe semi-rigid coax?) which passes through the wall of the 9cm tube to a connector for 10GHz.  The backshort of the 22mm tube is either flat or perhaps has a long taper so it doesn't interfere too much with the 9cm horn fields.  The 9cm horn has a probe feed as usual.  Problem with that arrangement is that the feed for the 3cm horn is parallel to the electric field of the 9cm horn if both use the same polarisation.

The 9cm probe would normally be about 19mm long in a simple cylindrical horn, but as the ID is around 62mm, if I ran the 22mm tube right through the backshort, would I be able to excite the correct mode to get linear polarisation at the mouth of the 9cm horn?  I suppose I should model it and see what happens.  There was an article in DUBUS a couple of years ago with a 13/3cm dual horn which used that principle, but had four tapered probes fed in quadrature to get circular polarisation.  The clearances are a lot less stringent with 2.4 and 10GHz.

Is it worth pursuing this approach? Is there a trick to use a short horn near the opening but get the feed to it without upsetting things on 9cm?  I could use a loop or tee to excite the 10GHz feed, with a coax feed through the backshorts of the 9cm horn, but aren't they a bit more lossy than a probe? Also not easy to adjust.

Couple of renders and a wobbly animation of the initial (obviously hopeless) ideas at http://www.g4dbn.uk/?p=1442

The 3.4GHz horn without choke ring looks like this in real life, so just imagine the 10GHz bit of a lensed POTY hanging coaxially in space with a support disk of thin dielectric material:

I have a lawn tractor to repair now, plus a teetering pile of 'prints for machining jobs, hence no visit to Cardiff or playing in the contests this weekend.

Neil G4DBN

-- 
Neil
<a href="http://g4dbn.uk/"><small>g4dbn.uk</small></a>


Re: duel band feed

DD1US
 

Hi Neil.

 

Did you have a look at this approach from Rasto OM6AA:

 

http://www.om6aa.eu/A_Simple_S_X_Dual_Band_Coaxial_Feed_for_Satellite_Communication_FV.pdf

 

Kind regards

 

Matthias

 

www.dd1us.de

 

 

Von: UKMicrowaves@groups.io <UKMicrowaves@groups.io> Im Auftrag von Neil Smith G4DBN
Gesendet: Samstag, 7. März 2020 16:03
An: UKMicrowaves@groups.io
Betreff: Re: [UKMicrowaves] duel band feed

 

Here's a thought then. Imagine the 10GHz waveguide and lens from a POTY, with an HB9PZK lens in a 22mm tube, about 70mm long, supported coaxially within a cylindrical 9cm horn. At the mouth of the 9cm tube, the 22mm tube is supported by a thin disk of HDPE or cross-linked polystyrene which also seals the end 9cm horn against water and insects.. The 22mm tube has a probe feed, with an air-spaced coaxial tube (or maybe semi-rigid coax?) which passes through the wall of the 9cm tube to a connector for 10GHz.  The backshort of the 22mm tube is either flat or perhaps has a long taper so it doesn't interfere too much with the 9cm horn fields.  The 9cm horn has a probe feed as usual.  Problem with that arrangement is that the feed for the 3cm horn is parallel to the electric field of the 9cm horn if both use the same polarisation.

The 9cm probe would normally be about 19mm long in a simple cylindrical horn, but as the ID is around 62mm, if I ran the 22mm tube right through the backshort, would I be able to excite the correct mode to get linear polarisation at the mouth of the 9cm horn?  I suppose I should model it and see what happens.  There was an article in DUBUS a couple of years ago with a 13/3cm dual horn which used that principle, but had four tapered probes fed in quadrature to get circular polarisation.  The clearances are a lot less stringent with 2.4 and 10GHz.

Is it worth pursuing this approach? Is there a trick to use a short horn near the opening but get the feed to it without upsetting things on 9cm?  I could use a loop or tee to excite the 10GHz feed, with a coax feed through the backshorts of the 9cm horn, but aren't they a bit more lossy than a probe? Also not easy to adjust.

Couple of renders and a wobbly animation of the initial (obviously hopeless) ideas at http://www.g4dbn.uk/?p=1442

The 3.4GHz horn without choke ring looks like this in real life, so just imagine the 10GHz bit of a lensed POTY hanging coaxially in space with a support disk of thin dielectric material:

I have a lawn tractor to repair now, plus a teetering pile of 'prints for machining jobs, hence no visit to Cardiff or playing in the contests this weekend.

Neil G4DBN